High-tension electric switch



Nov. 24 1925. 1,562,738

G. A. BURNHAM HIGH TENSION ELECTRIC SWITCH- Filed April 23, 1921 1m high and possibly localized,

Patented Nov. 24, 1925.

- UNITED STATES I 1,562,738 PATENT OFFICE.)

GEORGE A. BURNHAM, F SAUGUS, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CONDIT ELECTRICAL OF MASSACHUSETTS.

MANUFACTURING COMPANY, A CORPORATION .HIGH-TENSION ELECTRIC swrrcn.

Application 1i1ea April 23, 1921. Serial No. 463,778..

3 To all whom it may concern:

Be it known that I, GEORGE A. BURNHAM, a citizen of the United States, residing at Saugus, in the county of Essex and State of 5 Massachusetts, have invented an Improvement in High-Tension Electric Switches, of which the following is a specification.

This invention relates to electric switches particularly adapted to control circuits of relatively high potential and has particular reference to a switch characterized by a cylindrical shell or casing adapted to contain oil and bearing a stationary contact memher at the bottom thereof; and a rod comprising a'movable switch member and movable through an aperture in the cover of said casing to engage and disengage the stationary contact member; and baflie plates in said 1 casing adapted to assist in quenching the are drawn between said rod and contact member during operation of the switch to interrupt the circuit.

An object of this inventionis to provide' a switch of thetype above set forth and specifically, to -p'rotect the cover of the receptacle and the baflie plates therein from damage due to the sudden generation of gaseous pressures within the switch.

A further object is generally to improve the construction andoperation of an electric switch of the type above set forth.

Certain features of. this invention are set forth in my Patent 'No. 1,413,156, issued April 18, 1922, and this invention has more particular reference tofthe adaptation of the principle disclosed in said patent to the type of switch herein. set forth. Other features of this invention are disclosed in a co-pending application'of Joseph N. Mahoney, Se-' rial No. 488,150, filed July 28, 1921, and assigned to Sears B.Condit.

Fig. 1 is a front view ofa switch embodying the invention with one of the switch units in section.

\ Fig. 2 is a front View of one units illustratinga modified manner of resiliently mounting'the oil receptacle.

As here shown the switch embodying the invention, includesthe cylindrical shell 10,-

usually of drawn steel and of substantial length as compared with its diameter and with means to absorb energy developed within the switch due to circuit interruption of the switch adapted to contain oil in which the switch members are immersed. Said shell or casing is formed with a reduced bottom portion or neck 11 adapted exteriorly to be received in a supporting structure hereinafter to be set forth, and adapted interiorly to receive the stationary contact member 12 which is electrically connected with the casing. The casing is provided with a cover 13 and said cover is formed with an annular flange which is received within the casing and in sliding contact and electrically connected with said casing.

Said cover is formed with. an aperture therethrough and a plate 14 is bolted on the cover over the aperture and bears an insulating bushing 15; arid said bushing has an aperture 16 therethrough through which the switch rod 17 is adapted tomove to make and break contact with the stationary contact member 12. Said switch rod is secured to the arm 18 of operating mechanism of more or less usual construction.

It is customary to mount two switch units side by side on a supporting structure" 19 and connect the units in series; and it is also common to provide a brush member secured to the arm 18 of the operating mechanism to make electrical contact with the covers of the two units whereby electrically to connect them and shunt theoilimmersed contacts. For this purpose it is desirable to establish electrical connection between the cover 13 and the casing 10-; and the flexible conductor 20 secured under a bolt 13 of the cover and a bolt 10 secured in the side wall '90 of the casing accomplishes the result.

The switch units are herein shown as sup-" ported on the base 21; and said base is supported on an insulator 22 carried by the supporting structure 19 and secured thereto by the stud 23 which forms one of the switch terminals.

Said base21 is formed with supporting means for thecasing 10 including the lugsv 25 disposed to provide an enclosure for the 9 reduced portion 11 of said casing and sup- .port it against lateral movement; and the springs 28 are received thereon and engage the cover and nuts 29 removably secured to said rods. This construction provides means whereby the cover may move upwardly with respect to the casing upon the occurrence of abnormal aseous pressure conditions within the switch and thereby reduce strains upon the cover, securing means bushing and the like which heretofore 1 ve sometimes been so great as to cause t e rupture of the parts enumerated.

In the modification illustrated in Fig. 2, said rods 27 are rigidly secured to the cover and the casing 10 is resiliently supported upon the compression spring received between the lugs 25 of the base 21. In this construction the casing yields relatively to the cover to increase the gas expansion space above the oil in the casing and reduce gas eous pressure within the switch and strains upon the switchscomponents resulting from such pressures.

The casing is provided with one or more bafiie plates 40 which are disposed in vertically spaced relation within the casing; and are provided with apertures 41 therein through which the switch rod 17 is extended.

It has been customary, heretofore, to secure said battles rigidly within the casing. I prefer to support said battles yieldingly in lace within the casing whereby they may yield relatively to each other and the casing to absorb shocks. A suitable structure for this purpose may include the vertically disposed rods 45 upon which said bafiles are slidably received, and compression springs 46 may serve yieldingly to support said plates in position. Said upper baflle plate may be fixed to the upper ends of said rods, as by the pins 47 and springs 48 may extend between said rods and the cover to maintain said rods andplate yieldingly in place.

It will be observed that, with the construe tion above set forth, the switch components subject to gaseous pressures, or it may be, impact of the oil within the casing thrown upwardly by the rapid generation of gas at the are are mounted to yield and thereby absorb shock and reduce the stresses in their connection with associated switchv compofer the latter arrangement which is shown" in Fig. 2, for the reason that the cover forms a contact member for the brush member, and it isdesirable that said cover be maintained in a fixed position relative to said brush member as with'the construction illustrated'in Fig. 1,-said coverlmay'conceivably be moved upwardly by gaseous prestive electrical connection bination of a cylindrical casing adapted tocontain oil, a contact member mounted in the bottom of and electrically connected with said casing, means to support said casing vertically in position including a cover disposed on top of said casing, and yielding means arranged to provide for a relative movement between said cover and receptacle, and an independently-supported switch rod vertically movable through an aperture in said cover to engage the contact member contained in the casing.

2. An electric switch having the combination of a cylindrical casing adapted to contain oil, a contact member mounted in the bottom of said casin and connected electrically with said cas ng means to support said casing vertically in position including a cover disposed on top of said casing and yielding means connecting said casing and supporting means arranged to provide for a downward movement of said casing due to circuit interruption, and an independent ly supported switch rod vertically movable through an aperture in said cover to engage the contact membercontained in the casing.

3. An electric switch having a relatively movable casing and cover, said casing adapted to form one of the poles of the switch, means yieldingly connecting them, and a flexible electric conductor secured in posiwith said casing and cover. v

4. An electric switclrhaving the combina tion of a casing, a contact member contained therein, a cover for the casing comprising 'a contact-member, movable switch mechanism including a switch rod arranged to engage the contact member within the casing, and a brush member arranged to engage the cover, said casing and cover arranged for relative movement therebetween upon a circuit interruption, and a flexible electric connector secured in positive electrical connection with said cover and easing] An electric switch having the combination of a fixed cover arranged to form a contact member of the switch, a relatively" movable cas'ng disposed beneath said cover, means yildingly to support said casing in position beneath said cover, a contact-member mounted in and electrically connected with said casing and a movable switchmember including an independently-sup- ,pbrted switch rod arranged to engage the contact member in'the casing and a brush member arranged to engage the cover of the casing.

6. An electric switch having the combination of a cylindrical casing, a cover for the casing, an insulating bushing having an aperture therein carried by said cover, a contact member contained within and electrically connected with said casing, a mov- Y able switch member including anindependently-supported switch rod movable within said bushin to engage said contact mem her and a brus member arranged to engage the cover, supporting means for said casing and cover arranged removably to support the cover and support the casing yieldingly beneath the cover.

7. An electric switch having the combination of a cylindrical casing, a cover for the casing, an insulating bushing having an aperture therein carried by said cover, a contact member contained within and electrically connected with said casing, a movable switch member including a switch rod movable within said bushing to engage said contact member'and a brush member arranged to engage the cover, supportin means 'for said casing and cover arrange removably to support the cover and support the casing yielding'beneatht e cover, said supporting means including a base, rods secured to said base extended upwardly along the casing and fixed tosaid cover, and a spring carried by said base engaging the lower portion of said casing. V v x 8. An electric switch having the combination of a cylindrical casing, a cover for the casing, an insulating, bushing having an aperture therein carried by said cover, acontact member contained within andelectrically connected with said casing, a movable switch member including a switch rod movable with said bushing to engage said contact member and a brush member arranged to en ge the cover, supportin' means for sai casing and cover arrange removably to en port the cover and support I the casing'yieldlngly beneath-the cover, said supporting means includin a base, rods secured to said base extend upwardly along the casing and fixed to said cover, and a spring carried by said base engaging the lower portion ot said casing, lugs carried by said base 'arran ed to engage the lower portion of said. casing and restrain'it from lateral movement and said cover having :1 flange received within the upper portion of said casingoand en'ga eable therewith to restrain it m-latera movement.

p v I name to this s 9, An electricswitch havinga cylindrical casing adapted to contain oil, a contact member mounted in the lower portion of said casing beneath the oil therein, a switch rod movable within said casingf'to engage said contact member, a battle plate having a vent aperture through it received in said casing under the cover and yielding supporting means for said bafile plate.

10.7 An electric switch-having a cylindrical casing adapted to contain oil, a contact member mounted in the lower portion of said casing beneath the oil therein, a cover for the casing, a switch rod movable within said' casing to engage said contact member, a baflle plate having a vent passage through it received in said casing under the-cover, and'means yieldingly to support said baflle plate in position.

11 An electric switch having a cylindri cal casing adapted to contain oil, a contact member mounted in the lower portion of said casing beneath the oil therein, a cover a baflie plate received in said casing under the cover, and means yieldingly to support it in positionincluding rods on which said plate is slidably' received, and springs arranged on said rods to support said plate yieldingly in position.

12. An electric switch including a cylindrical oil receptacle, flexible means to support said receptacle yieldinglyincluding. a support disposed beneath said receptacle, a spring carried by said support and disposed in engagement with the bottom of said oil receptacle in the middle of said bottom, and inflexible means to'support said receptacle movably in vertical position on said spring.

13. An electric switch including a. support, a helical compression spring carried by said support, and'a cylindricaloil receptacle having its bottom resting on'said spring with the. axis of said receptacle approximately co-incident with the axis of said spring.

. 1.4. An electric switch including an oil j receptacle-having a reduced neck at the bottom thereof, and yielding supporting means in engagement with said neck.

15. An'electric switch having a relatively In testimony w ereof, I have signed my cation. ORGE A. B NHAM. 

